Vitamin D status of children with Paediatric Inflammatory Multisystem Syndrome Temporally associated with Severe acute respiratory syndrome coronavirus 2 (PIMS-TS).

Coronavirus disease 2019 (COVID-19), has caused mild illness in children, until the emergence of the novel hyperinflammatory condition PIMS-TS: Paediatric Inflammatory Multisystem Syndrome Temporally associated with Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). PIMS-TS is thought to be a post- SARS-CoV-2 immune dysregulation with excessive inflammatory cytokine release. We studied 25 hydroxyvitamin D (25OHD) concentrations in children with PIMS-TS, admitted to a tertiary paediatric hospital in the United Kingdom (U.K), due to its postulated role in cytokine regulation and immune response. Eighteen children [median (range) age 8.9 (0.3 to 14.6) years, male=10] met the case definition. Majority were of Black, Asian and Minority Ethnic (BAME) origin [89%, 16/18]. Positive SARS-CoV-2 IgG antibodies were present in 94% (17/18) and RNA by PCR in 6% (1/18). 72% of the cohort were vitamin D deficient (<30nmol/L). The mean 25OHD concentration was significantly lower when compared to the population mean from the 2015/16 National Diet and Nutrition Survey (children aged 4-10 years) [24 vs 54nmol/L (95% CI: -38.6, -19.7); p<0.001]. The PICU group had lower mean 25OHD concentrations compared to the non-PICU group, but this was not statistically significant [19.5 vs 31.9 nmol/L; p=0.11]. The higher susceptibility of BAME children to PIMS-TS and also vitamin D deficiency merits contemplation. Whilst any link between vitamin D deficiency and the severity of COVID-19 and related conditions including PIMS-TS requires further evidence, public health measures to improve vitamin D status of the U.K BAME population has been long overdue

Serology confirms SARS-CoV-2 infection in PCR-negative children presenting with Paediatric Inflammatory Multi-System Syndrome.

Background During the COVID-19 outbreak, reports have surfaced of children who present with features of a multisystem inflammatory syndrome with overlapping features of Kawasaki disease and toxic shock syndrome - Paediatric Inflammatory Multisystem Syndrome- temporally associated with SARS-CoV-2 pandemic (PIMS-TS). Initial reports find that many of the children are PCR-negative for SARS-CoV-2, so it is difficult to confirm whether this syndrome is a late complication of viral infection in an age group largely spared the worst consequences of this infection, or if this syndrome reflects enhanced surveillance. Methods Children hospitalised for symptoms consistent with PIMS-TS between 28 April and 8 May 2020, and who were PCR-negative for SARS-CoV-2, were tested for antibodies to viral spike glycoprotein using an ELISA test. Results Eight patients (age range 7-14 years, 63% male) fulfilled case-definition for PIMS-TS during the study period. Six of the eight patients required admission to intensive care. All patients exhibited significant IgG and IgA responses to viral spike glycoprotein. Further assessment showed that the IgG isotypes detected in children with PIMS-TS were of the IgG1 and IgG3 subclasses, a distribution similar to that observed in samples from hospitalised adult COVID-19 patients. In contrast, IgG2 and IgG4 were not detected in children or adults. IgM was not detected in children, which contrasts with adult hospitalised adult COVID-19 patients of whom all had positive IgM responses. Conclusions Strong IgG antibody responses can be detected in PCR-negative children with PIMS-TS. The low detection rate of IgM in these patients is consistent with infection having occurred weeks previously and that the syndrome onset occurs well after the control of SARS-CoV-2 viral load. This implies that the disease is largely immune-mediated. Lastly, this indicates that serology can be an appropriate diagnostic tool in select patient groups